Fluorescent lamps have been widely used for a variety of commercial, industrial, consumer, and other lighting applications including, as an important but non-limiting example, commercial signage since the 1930's. More recently, lamps employing one or more light emitting diodes (LEDs) as the primary source of illumination have created a market for retrofitting signs containing fluorescent tubes with LED-based products or devices. Some of the benefits of LED lighting include, without limitation, reduced energy consumption, longer service life, safer and less hazardous materials, and a less complex and less expensive power supply. The enormous installed base of illuminated signs employing fluorescent tubes makes it desirable to implement LED retrofit products that can be installed directly into the existing fluorescent tube sockets. However, the power source for a fluorescent tube generally includes a ballast to control and limit the flow of current to the fluorescent tube. In contrast, LED lamps are generally powered by a DC power supply that provides a constant or substantially constant supply voltage and/or supply current. As a result, it is not generally feasible to install an LED lamp product in the fluorescent tube socket without disconnecting, modifying, or replacing the power circuit coupled to the socket.